Priceiella (Thescelovora) chanthaburiana Gustafsson, Clayton, & Bush, new species

(Figs 22–28)

Type host. Megapomatorhinus hypoleucos tickelli Hume, 1877 —large scimitar-babbler ( Timaliidae).

Type locality. Khao Soi Dao Tai, Chanthaburi Province, Thailand.

Other host. Pomatorhinus schisticeps klossi Baker, 1917 —white-browed scimitar-babbler ( Timaliidae).

Diagnosis. Priceiella (Thescelovora) chanthaburiana n. sp. is most similar to P. (T.) austini n. sp. The relatively broad preantennal area and deeply concave frons of P. (T.) chanthaburiana (Fig. 24) is similar to the shape of the preantennal area in P. (T.) austini n. sp. (Fig. 10), but the lateral margins of the preantennal area are clearly convex in P. (T.) chanthaburiana, rather than straight or slightly concave as in P. (T.) austini . The dorsal preantennal suture is absent in P. (T.) chanthaburiana (Fig. 24), but is present in P. (T.) austini as well as in other similar species [ P. (T.) fuscicaena n. sp. and P. (T.) malacocincla (Najer, pers. comm.)]. The lateral thickenings of the gonopore do not curl around the pmes in P. (T.) chanthaburiana (Fig. 26) as they do in P. (T.) austini (Fig. 12) and P. (T.) orichalca n. sp. (Fig. 21). Unlike in P. (T.) austini (Fig. 12) and P. (T.) orichalca (Fig. 19), there are 2 pmes antero-lateral to the gonopore in P. (T.) chanthaburiana (Fig. 26) and no discernable pmes on lateral margin distal to the rugose nodi; but these pmes may be overlooked due to being sensilla. The proximal mesosome of P. (T.) chanthaburiana (Fig. 26) is rectangular as in P. (T.) orichalca (Fig. 19), whereas the distal section of the mesosome in P. (T.) chanthaburiana is more similar in shape to that of P. (T.) austini (Fig. 12). Male tergopleurites VI–VII have aps in P. (T.) chanthaburiana (Fig. 22) as in P. (T.) austini (Fig. 8), but these are absent in P. (T.) orichalca (Fig. 15) and P. (T.) malacocincla .

Description. Both sexes. Head broad, dome shaped with a flat posterior margin (Fig. 24). Frons deeply concave. Lateral margins of preantennal head convex. Dorsal preantennal suture absent. Head chaetotaxy as in Fig. 24. Coni reach distal margin of scape. Pteronotum with 5 mms on each side (Figs 22–23). Marginal and marginal temporal carinae, head nodi, flagellomeres, proepimera, metepisterna and pleural incrassations dark brown; mandibular framework and gular plate medium brown; metasternum and sternal and subgenital plates pale brown, progressively darker in more posterior segments.

Male. Abdominal plates and chaetotaxy as in Fig. 22; aps present on tergopleurites VI–VII (may be absent on one side). Male genitalia as in Figs 25–27. Basal apodeme broad, slightly constricted at mid-length (Fig. 25). Proximal mesosome broad, rounded rectangular (Fig. 26). Mesosomal lobes gently rounded with medial point. Ventral node rugose apically. Lateral thickening of mesosome sinuous, interrupted medially. Marginal thickenings of gonopore do not curl around pmes anteriorly; 2 ames sensilla on each side near antero-lateral portions of mesosomal lobes; 2 pmes sensilla on each side of gonopore. No lateral pmes are visible distal to gonopore; these may be overlooked due to being sensilla. Parameral heads large, irregular in shape with clearly serrated posterior margin and slight constriction on anterior margin (Fig. 27). Parameral blades stout, slightly divergent distally; pst1–2 close together. Measurements ex Pomatorhinus hypoleucos tickelli (n = 7): TL = 1.35–1.55; HL = 0.33– 0.34; HW = 0.35–0.36; PRW = 0.20–0.21; PTW = 0.32–0.33; AW = 0.44–0.53. Measurements ex Pomatorhinus schisticeps klossi (n = 3): TL = 1.35–1.50; HL = 0.33–0.34; HW = 0.34–0.36; PRW = 0.20–0.21; PTW = 0.30– 0.32; AW = 0.42–0.45.

Female. Abdominal plates and chaetotaxy as in Fig. 23. Vulval margin gently rounded (Fig. 28), with 2–3 slender vms and 4–5 thorn-like vss on each side. Medialmost vms shorter than vss; 4–6 long, slender vos on each side; distal vos anterior to vss. Measurements ex Pomatorhinus hypoleucos tickelli (n = 7): TL = 1.55–1.69; HL = 0.35–0.36; HW = 0.38–0.39; PRW = 0.22–0.23; PTW = 0.34–0.35; AW = 0.50–0.54. Measurements ex Pomatorhinus schisticeps klossi (n = 3): TL = 1.49–1.64; HL = 0.34–0.35; HW = 0.36–0.38; PRW = 0.20–0.22; PTW = 0.32–0.34; AW = 0.45–0.51.

Etymology. The species epithet is derived from the type locality.

Type material. Ex Megapomatorhinus hypoleucos tickelli: Holotype Ƌ, Khao Soi Dao Tai, Chanthaburi Province, Thailand, 21 Mar. 1966, 24705 on reverse (OSUS) . Paratypes: 6♂, 7♀, same data as holotype, 24705– 24711 on reverse (OSUS) .

Additional material examined (non-types). Ex Pomatorhinus schisticeps klossi: 3♂, 3♀, Khao Soi Dao Tai, Chanthaburi Province, Thailand, Feb.–Mar. 1966, 24717–24719 on reverse (OSUS).

Remarks. No significant differences have been found between material from the two host species. Males from P. schisticeps generally have a more pointed proximal mesosome and slightly longer and more bent parameres than material from P. hypoleucos, but individual variation overlaps between specimens from the two hosts. Females from P. schisticeps tend to have fewer vos (4–5) and more vss (5–7), but the overlap in both characters is large, and vulval setae are typically asymmetrical and variable between individuals. All examined material from both host species was collected at the same locality during the same period.